Drawing



D. J. McEvoY Erm.

DRAWING INSTRUMENT Feb. 22, 1944.

Filed May 14, 1942 I nventor By ad muy HM Atmos Patented Feb. 22, 1944 DRAWING INSTRUMENT Daniel Joseph McEvoy, and Patrick J. McEvoy, Chicago, Ill.

Application May 14, 1942, Serial No. 442,962

3 Claims.

'I'he present invention relates to new and useful improvements in drawing instruments, and has for its primary object to provide, in a manner as hereinafter set forth, a device of this character comprising a rule including novel means whereby circles of substantially any diameter within a given range may be expeditiously scribed. t

Other objects of the invention are to provide a drawing instrument of the aforementioned char- `acter which will be comparatively simple in construction, strong, durable, highly efiicient and reliable in use, compact, light in weight, and which may be manufactured at low cost.

All of the foregoing and still further objects and advantages of the invention will become apparent from a study of the following specification, taken in connection with the accompanying drawing wherein like characters of reference designate corresponding parts throughout the several views, and wherein:

Figure 1 is a plan view of a drawing instrument constructed in accordance with the present invention.

Figure 2 is an edge view thereof.

Figure 3 is a perspective view on an enlarged scale of an end portion of the device.

Referring now to the drawing in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a rule in the form of a bar -I of suitable length, width and thickness, said bar being of any desired material. For a maior portion of the length of the bar I, the longitudinal marginal portions of said bar are provided with graduations 2. Openings 3 are provided in the bar I at the inner vends of the graduations 2. The bar I is further provided. in its end portions, with openings 4. 'I'he bar I is still further provided, in one end portion, with various shapes of openings or slots 5 to facilitate the scribing of various angles.

This end portion of the bar I also has formed therein a transversely elongated recess 6 comprising a reduced end portion 1. Adjacent the recess 6, an opening 8 is formed in the bar I. A resilient clip 9 is mounted in the lopening 8.

The recess 8 forms what may be considered a pocketfor the reception of a pivot pin II. The reduced portion 'I of the recess 6 accommodates a point I2 on one end of the pivot pin II.

The pivot pin II has formed therein a circumferential groove I3 in which the resilient clip 9 is. engageable for releasably securing the pivot pin II to the bar I.` The pivot pin II also has formed therein a longitudinal channel I4 in which a transverse tonsue I5 on the bar I is engageable. It will thus be seen that the pivot pin I I, when it is not in use, is firmly but detachably secured in position on one end of the bar I.

It is thought that the manner of using the instrument will be readily apparent from a consideration of the foregoing. Briefly, the pivot pin II is removed from the board I and inserted through one of the openings 4 for causing the point I2 to penetrate the work for pivotally anchoring said bar thereto. The point of a pencil is then inserted through one of the openings or perforations 3, according to the diameter of the circle to be scribed, and the bar I is swung in a circle around the pivot pin II.

It is believed that the many advantages of a. drawing instrument constructed in accordance with the present invention will be readily understood, and although a preferred embodiment of the device is as illustrated and described, itis to be understood that changes in the detailsof construction and in the combination and arrangement of parts may be resorted to which will fall within the scope of the invention as claimed.

What is claimed is:

1. A drawing instrument comprising a bar having a recess in one end portion, said bar further having an opening therein adjacent the recess, a pivot pin for the bar removably mounted in the recess when not in use, said pivot pin having a circumferential groove therein, and a resilient clip mounted in the opening, and engageable in the groove for releasably securing the pivot pin in the recess.

2. A drawing instrument of the character described comprising a bar having a transversely elongated recess in one end portion, said recess including a reduced end portion, said bar further having an opening therein adjacent ythe recess, a tongue on the bar, apivot pin for the bar removably mounted in the recess and including a point on one end engaged in the reduced portion of said recess, said pivot pin having a channel therein for the reception of the tongue, and a resilient clip mounted in the opening and engageable in the groove in the pivot pin for releasably securing said pivot pin in the recess.

3. A drawing instrument comprising a bar having a transversely elongated recess in one end portion, a tongue on the bar, a pivot pin tor the bar removably mounted in the recess and having a channel therein for the reception of the tongue, and ymeans for releasabiy securing the pivot pin in the recess.

DANIEL JOSEPH McEVOY. PATRICK J. McEVOY. 

